Early Brain Development and Nature vs Nurture

The nature vs nurture debate is one of the oldest and most important questions in psychology. It asks whether our behaviour, abilities, and characteristics are primarily determined by our genes (nature) or by our environment and experiences (nurture). In the context of development, this debate is central to understanding how children learn, grow, and develop.

Nature

The nature side of the debate argues that our characteristics are primarily determined by biological factors — our genes, brain structure, hormones, and neurochemistry. According to this view, development follows a predetermined biological programme.

Evidence for Nature

Twin studies — identical (monozygotic) twins share 100% of their DNA. If a trait is entirely genetic, identical twins should always show the same trait. Studies show that identical twins raised apart often show striking similarities in personality, intelligence, and behaviour
Maturation — certain behaviours appear at predictable ages regardless of environment (e.g. all children learn to walk at roughly the same age), suggesting a biological timetable
Innate reflexes — newborn babies show reflexes (grasping, sucking, rooting) that are present from birth without learning
Brain structure — the basic structure of the brain is determined genetically

Nurture

The nurture side argues that our characteristics are primarily shaped by environmental factors — our upbringing, education, culture, social relationships, and experiences.

Evidence for Nurture

Cultural differences — children raised in different cultures develop different values, behaviours, and cognitive styles, suggesting that environment shapes development
Effects of deprivation — children who experience severe neglect or deprivation (e.g. Romanian orphans) show significant developmental delays, demonstrating the importance of environmental stimulation
Education — formal education dramatically improves cognitive abilities, showing that learning environment matters
Language — children learn the specific language of their environment, not a genetically determined language

The Interactionist Approach

Most psychologists today believe that the answer is not either nature or nurture but an interaction between the two. This is called the interactionist approach:

Genes provide the potential for development, but the environment determines how that potential is realised
For example, a child may have a genetic predisposition for high intelligence, but without a stimulating environment and good education, that potential may not be fully developed
Conversely, the most enriching environment cannot produce abilities beyond a person's genetic potential

Epigenetics

Recent research in epigenetics has shown that environmental factors can actually influence how genes are expressed without changing the DNA itself. This means that nature and nurture are even more intertwined than previously thought — the environment can switch genes on or off.

Nature vs Nurture in Development

Aspect of Development	Nature (Biological)	Nurture (Environmental)
Intelligence	Genetic potential for cognitive ability	Education, stimulation, nutrition
Language	Innate capacity for language (Chomsky's LAD)	Exposure to specific language in environment
Personality	Temperament (genetically influenced)	Parenting style, culture, experiences
Motor development	Biological maturation	Opportunities for practice

Key Points

The nature vs nurture debate asks whether development is driven by biology or environment.
Nature = genes, biology, maturation; Nurture = environment, experience, learning.
Most psychologists favour the interactionist approach — both nature and nurture interact.
Epigenetics shows that environment can influence gene expression.
Understanding this debate is essential for evaluating theories of development (e.g. Piaget, Dweck).